Island



(No Model.)

J. G. SGHRADEB..

BXPLODER FOR BLASTING CARTRIDGES.

Patented Feb. 21,1882.

INVENTOR.

wia-messes.

y. UNITED STATES PATENT muon.

JOHN C. SOHRADER, OF WARWICK, RHODE ISLAND.

ExPLoDE'R Fon BLASTiN'o-cARTRIDGEs.

SPECIFICATION forming parc of Letters iPatentNo. 253,s93,"d'ated February e1, 1882.

Y Application filed August 11, 1881. (No model.)

t To all whom it may concern:

Beit known that I, J oHN C. SCHRADER, of Warwick, in the county of Kent and State of Rhode Island, have invented a new and useful Improvement in Gartridge-Exploders; and I do hereby declare. that the following specification, taken in connection with the accompanying drawings, forming a part ot' the same, is a full, clear, and exact description thereof.

My exploder is especially intended for use in blasting in coal and other mines, but is adapted and will be useful for exploding cartridges for other purposes. I make use of the tubular blasting-bar heretofore commonly used in blasting in coal-mines in place of a safetyfuse, which is comparatively expensive.y This tubular blasting bar'extendst'he entire length oftbehole which has been drilled in the material to be blasted, and which in coal-miningis usually not less than six feet in depth, Heretofore it has been customary to simplyinsert thelower end of this tubular blasting-bar into the neck of a cartridge of powder and tie the neck ot' -the cartridgermly around the blasting-bar.

The blasting-bar and cartridge having been y placed in the drilled hole and the hole having been properly tamped with pieces of coal, dry sand, or other suitable material, a squib composed of a straw filled with powder, or of other Well-known construction, was inserted into the external end of'the tubular blasting-bar and lighted. This squib, by the force of the powder contained therein, was caused to dart along the length of the blasting bar'or tube, and, while still ignited, to come in contact with,ig

nite, and explode the mass of powder in the cartridge. With this means for exploding the cartridge the powder in the cartridge would at rst be'ignited only at that Aend of the mass with which the lighted squib first comes -in contact, and the lire thus started has to travel the length of the mass of powder before it is all ignited. To obtain the best results in blasting with powder it is necessary that the entire mass should be exploded as simultaneously as possible. To accomplish this I employ a cap of fulminating mercury or other suitable fulminate to explode the mass of powder, which fulminate,-upon being exploded, shoots avolurne of re into the mass ot' powder and ignites instantly a much larger quant-ity than can be ignited by a squib or a fuse.

`of powder; but in all such attempts the cap has been so inserted in the lower end of the tubular blasting-bar that the fulminate cou- Y tained in the cap has come within the blasting bar or tube. This has been attended with two serious diiiculties: First, the explosion ofthe fulmnate in this position was almost certain torend lor split the blasting-bar, which, when reduced below a certain length, becomes useless for the purpose required; and, secondly, when it' for any reason the squib should fail to explode the fnlminate it becomes necessary, as it sometimes does, to clear the blasting bar or tuheof any'pteces otccal oroth er matter which might interfere with the passage of a new squib, there was great danger ofcausing a premature explosion of thccap and cartridge by reason of the liability of hitting or scraping the fulminate in the cap with the scraper or cleaner used for clearing the blasting-tube.

`For the above reasons it has heretofore been also impracticable in coal and similar blasting to use, in connection with a blasting-tube and a squib, dynamite, nitro-glycerin'e, or any one of that classof higher explosives which require a fulmiuating-cap to explode them, although I have discovered by numerous experiments that this class ot' explosives-and especially those of alow degreecan be used to great advantage in blasting of this kind.

The object of my invention is to make practicable the use of a fulminatingcap in connection with a blasting-tube and a squib to explode a cartridge, and thus to make also prac ticable the adoption and employment of that class of higher explosives requiringlthe use of a fulminatingcap for their explosion; and my invention consists in so locating the cap containing the fulminate with reference to the blasting bar or tube that the entire quantity of the fulminate shall lie below the plane of thelower end of the blasting bar orgtnbe; and it also consists in so constructing the metallic cap containing the fulminate, or so providing it with a protector, that while a channel is furnished for communicating fire from the squib to the fulminate, this channel is of such a nature or `ot' such a construction that the fulminate is protected from being exploded ICO Yby percussion or friction, and the scraper or of device containing my invention, and Fig. 2 represents, likewise in longitudinal vertical section, another form of device for the same.

A in both figures represents the tubular blasting-barVwhich is inserted i-n the neck of the cartridge B, which is filled with powder, dynamite, nitro-glycerine, or other explosive, b, to be used, the neck of the cartridge being firmly tied to the blasting-bar by a string, as at a.

C is the cap containing a quantity of fulminating-mercury or other suitable fulminate, D, which cap in the device represented at Fig.-2 is of about twice the length of that in Fig. 1, and is provided at its upper end with .the flange c.

In the device shown in Fig. 1 the cap C is provided with a protector, E, made of any suitable materialas wood, for instancewhich protector .E has a longitudinal bore., c e', through its entire length. of sufficient diameter to receive the cap containing the fulminating-mercury or other fulminate. That portion of the bore e e' not occupiedby, the cap C is filledy with powder, guncottou,-or other easily -inammable material, as at b. This bore is enlarged at its upper end to the full size of the protector E,'in order that-if the squib should be diverted in its course from the center of the blasting bar or tube it may still come in contact with easily-inflammable matter, and over the top of the protector,when powder is used to fill the bore, I usually place, to keep the powder from spilling, adiaphragm of paper, d, soaked with niter orv other substance to render it readily inflammable. The longitudinal bore c c',l and the powder, guncotton, or other material contained therein,

furnishes a channel or means of communication for the fire from the squib to reach the' fulminate D, and the powder, gun cotton, or other inflammable matter thus placed above the fulminatc prevents the scraper from 'com ing in contact therewith and protects it from being exploded by percussion or friction.

If desired, the protector E may be Aso constructed as of itself and apart from the powder or gun-cotton contained therein to prevent the scraper from coming in contact with the fulminate. This may be accomplished, as shown in Fig. l of the drawings, by making the lon,- gitudinal boree e of two different diameters, the lower portion, e, of said bore being of sufticient diameter to receive the cap containing bore being of smaller diameter than the portion e, and of smaller diameter than vthe diameter of the scraper used for clearing the blastin g-tube. With this construction (and it is the ployed,

one which I prefer to make use of) the size of the upper portion of the bore in the protector effectually prevents the entrance of the scraper and protects the fulminate from explosion by percussion or friction. The protector E is attached to the lower end of the blasting bar or tube A by a short tube of parafiined paper, F, or other suitable connection, into one end of which tube the protector E is inserted, and the other end of which tube surrounds the lower end of the tubular blasting-bar, to which it isv firmly tied by a string, as at a'. y

In the device represented at Fig. 2 the cap Gis provided with a quick fuse, G, composed of any suitable combustible materia-l which is sensitive enough to take tire from the least spark from the squib, but which cannot be ignited by percussion or friction. One end of this quick fuse G is iuserteddnto thevupper ex; tended end of the cap C above and extending down to the fulminate D, and -tbeother end lof the-fuseG enters the lower end of the blasting bar or vtube A, the fuse vGr thus forming the connection between 4the cap and the blastingtube. The flange lc upon the upper end ofthe cap Cabuts against the-lower end of the blasting-,tube A,and prevents the cap from being in anyway forced into the blasting bar or tube. The fuse G constitutes the -channel or means to communicate the fire from the squib to the fulminate' D in the cap C, and at the same time prevents the scraper or cleaner from coming in ,contact with or exploding the fulminate, the

fuse being insensitive to percussion or friction.

The operation of the device represented -in Fig. l is as follows: The parts having been placed in position with reference to each other, as shown in the, figure, and properly united, thedevice is inserted to the proper depth -in the hole that has been drilled in the material to be blasted. The hole-is then tamped in the usual manner, and the squib, having been introduced into the upperfend ofthe vtubular blasting-bar A, is lighted. The force of the powdervin the squib carries it along the blast ing bar or tube until it reaches the lower end of the tube. The lightedfsquib therecomes in IOO tof,

ILO

contact with the paperdiaphragm d, if one -is l used, or, if not, directlywith the powder, guncotton, or other inflammable matter,-b,` and immediately ignites it. The'flame is carried through the inflammable matter in the chan nel orA bore e c to the fulminate D and explodes it, and thefulminate in turn forcibly explodes the cartridgeDby means of thevolumeof flame which it shoots into the mass, if powder be emor by means of the percussion'caused by the capC, if-the cartridge fbe one of dynai mite, nitro-glycerine, or one of the higher explosives requiring afulminating-cap to explode 1 it.' thefulminate, and the upperportion, e', of said The operation of the device represented -n Fig. 2 is similar to that ofthe device already described. The same preparatory steps hav ing been taken, the squib, when it reaches the lower end of the blastingtube A, comes in com -a small quantity of loose powder, which is directly lred by a squib, as in Fig. 1, or indirectly fired by the squib through a short length of fusewithin the firing-tube, as in Fig. 2. I'

am aware that fulminate-exploders of various kinds have heretofore been employed in combination with cartridges and arranged to be tired by means of safety-fuses, and also by electrical apparatus; but so far as I know I amthe first to provide for iiringfulminate-exploders by means of squbs, as by the firing tube or bar, and I have so combined the fulminate'exploder and cartridge with the firing-tube that the fulminate is protected from being fired by the percussion or friction incident to or liable in the use of clearing-tools within the firing-tube, asis frequently requisitein practical operations.

While I have represented in the drawings and have described two specilc devices for carrying my invention into eifect,-I do not mean tolimitmyself to the peculiar devices described,

' as it is evident that a variety of different ways may be devised for .accomplishing the results specilied which would embody the principles of my invention-as, for instance, the cap containing the fulminate may be so constructed as by contracting its upper portion to prevent the admission of the scraper used for clearing the blasting-tube, and at the same timeffurnish a proper and sufiicient channel for the transmission of the llame. It-is obvious, too, that instead of providing a single channel or opening, several might be employed, as by furnishing the top of the extended cap with a perforated diaphragm which would arrest the scraper,

but allow the communication of the iiame to to the powder or other inflammable matter contained in the cap.

What I do claim as my invention, and desire'to secure by Letters Patent, is-

1. The combination, substantially as herein` before described, of the tubular blasting tube or bar, the cartridge connected therewith, and a fulminate-exploder connected with the blasting-tube, located within the cartridge and beyond the end of said tube, as and for the pur poses specified:

2. The combination, substantially as hereinbefore described, ot' the tubular blasting tube or bar, the cartridge connected therewith, and a fulminateexploder connected with the inner end of said tube within the cartridge and communicating with said tube for tiring purposes by'way of a passage or channel of lesser diameter than that of the blas tingbar, as and for the purposes specified.

.JOHN C. SCHRADER.

Witnesses: 4

W. H. THURSTON, I. KNIGHT. 

